Cheap Antenna Analyzer

Cheap Antenna Analyzer

Background

Recently, I stumbled upon 4X6UB’s post (can be found here) about his cheap HF antenna analyzer.
Since I don’t have one and buying MFJ or others are expensive (Besides, building one is much more fun than buying), I sent him a message and he was kind enough to help me build one as well.
This one is based on K6BEZ‘s design but Ido (4X6UB) did some changes.

The build

This antenna analyzer can operate from 0-30 MHz so no V/U bands here.

It’s based on few components that you can get for cheap on eBay or AliExpress.
The main PCB is custom made so you’ll need to print it or get it somehow.
So, what’s inside?

Full graphics LCD for 3D printers (10$)

PCB

AD9850 Signal Generator (15$)

Arduino Pro Micro (6$)

BNC Connector

Some other parts

Soldering the parts to the PCB is quick and easy.
We got some resistors, capacitors, OP Amp and few germanium diodes.
Then we just need to connect all together with the headers and pins.
I added 9V battery with regulator so I can power it without the Arduino USB connection.

Case

I designed a case in Fusion360 and after some failed prints I got it right.
This case need a redesign because it’s bulky but for now I’ll stick with it.

Testing and comparison

Power

The power consumption is around 120ma when idle and 170ma when running a scan.

SWR

I did compare it to Comet and RigExpert meters.
My measurement is not 100% accurate because I didn’t try different bands.
The first antenna was dipole for 20m and tested with RigExpert.
The second antenna was 6m dipole but it’s out of my measuring range so I tested it in on the lowest SWR that my meter showed versus the comet meter (which has small deviation according to its owner)

Frequency

My Meter

RigExpert

Comet

14.200

1.2

1.3

15.500

2.7

3.4

Pictures

Conclusion

For my needs it’s awesome and I’ll use to it to tune my new dipole antenna on my new QTH.
Also, I’m working on Magnetic Loop antenna and this analyzer will be very helpful.